1. Field of Art
This invention relates to the field of surgical equipment for use in the practice of medicine and, in particular, relates to an improved resectoscope.
2. Prior Art
A conventional resectoscope for internal surgery generally comprises an operating handle with two sections that slide forward and backward relative to one another under the control of an operator using finger and thumb grips; various extensions protruding from one or the other of the handle sections (for relative movement) which may include a cutting instrument, a telescope for viewing the site of the surgery, a light conduit to illuminate the site, and a means for providing an aspirating fluid to lubricate and to wash the site, and a pair of coaxial tubes which contain the extendible parts and shield them from the patient except at the distal end of the tubes. The inner tube extending from the handle typically encloses the telescope, light conduit, and cutting instrument. An outer tube or atraumatic meatus stopper surrounds the inner tube. The aspirating fluid may wash the tip of the telescope to maintain clear viewing, distend flesh about the cutting instrument, collect surgical morsels from the cutting instrument, and carry them back through the resectoscope to a collection device where the morsels may be filtered from the fluid. Other attachments are known, for example, a video camera may be connected to the telescope to display the surgical site on a television monitor. The cutting instrument may be one of many known types such as: a cutting loop, a roller ball, a roller bar, or an electrode. Electric circuits may be provided within the resectoscope tubes to power such instruments. Examples of prior art patents disclosing similar devices are discussed below.
U.S. Pat. Nos. 3,835,842, and 3,850,175, relate to endoscopic urological devices that provide a conduit for the inflow of clear irrigating fluid to the operative field, and an outflow conduit for removing turbid fluid from the field using suction. The conduits are formed by providing an inner sheath within an outer sheath.
U.S. Pat. No. 5,176,677 relates to a surgical instrument with a hand piece, a vibration source to effect cutting of tissue, a telescope, and an irrigation system. It discloses the use of an ultrasonic surgical device that provides both irrigation and aspiration as well as tip rotation. An electro-cauterizing current is provided in the cutting tip of a cutting instrument. A telescope near the cutting tip permits the surgeon to view the tissue. Irrigation of the site with aspirating fluid is provided through a luer fitting to improve visibility through the telescope and to wash tissue back through a hollow tip into a suitable collection vessel.
U.S. Pat. No. 5,456,689 relates to a tissue resection device in which tissue morsels are removed from the cutter through an aspiration lumen within the shaft. As the aspirated fluid is withdrawn, the morsels from the surgery are trapped and separated from the aspirated fluid by a filter screen. The viewing tube is surrounded by the inflow passageway and the morsels are withdrawn through a tube which supports the cutting instrument.
U.S. Pat. No. 5,201,731 relates to a resectoscope for prostate surgery with a rotating cutting element mounted within an outer tube. In addition to the rotating cutting blade, there is a laser light beam fed through an optic filament to cut and coagulate the resected area. Irrigation is provided to the area between inner and outer tubes and is withdrawn through the inner tube. The surgeon can view the cutting operation through a telescope provided through the cutting element. The chips or morsels of tissue are withdrawn with the irrigation fluid through the inner tube.
U.S. Pat. No. 5,542,929 discloses an aspiration device with side valves for reducing whistling noise when the aspirator is under pressure.
U.S. Pat. No. 5,527,331 relates to a tissue resection device having a rigid tube with second drive tube rotatably located within it and a cutting head mounted on the drive tube. Resection is achieved by either conventional cutting or electrocautery. An optic fibre is used for viewing. The morsels removed by the cutter are extracted immediately through the aspiration lumen in the rotating shaft. A disposable cartridge filters the surgical debris.
Other patents of interest include U.S. Pat. Nos. 5,542,928; 5,542,918; 5,542,917; 5,540,683; 5,540,679; 5,540,678; 5,540,658; 5,540,656; 5,536,234; 5,314,438; 5,313,949; 5,133,713; 5,000,185; and 4,681,106.
There is a limit in the size of a resectoscope which is determined by the comfort of the patient and the manipulation requirements of the surgeon. This size limitation becomes significant when one wishes to remove surgical morsels for testing and further examination. For example, an outer tube, which contains all the various elements that extend into a patient, may be about 8 to 9 mm in outside diameter. An inner tube may be about 7 mm in outside diameter. A standard telescope may be about 3-3.5 mm. The conventional structure of concentric inner and outer tubes provides a passage between them of significant cross-sectional area, but the radial difference between the tubes is small. Without going into further detail, it may be appreciated that the conventional structure limits the free space for passage of aspirating fluid and it may become blocked when the fluid from the surgical site contains clots, coarse debris, and tissue.
The present invention is directed to a novel structure of a resectoscope to increase the ability to transmit aspirating fluid and surgical debris through the resectoscope. The new structure does not have an inner tube and outer tube, but, rather, one tube divided in cross section by a longitudinally extending wall into a first segment and a second, larger, segment to form passageways for the aspirating fluid and the parts of the resectoscope that extend to the surgical site. The first passageway is sized to carry a telescope and a light conduit and to provide some free space for incoming clear, aspirating fluid. The second passageway occupies the balance of the cross section of the tube for the removal of surgical debris.
More precisely, one embodiment of the invention is a resectoscope for surgery at an internal surgical site comprising:
an operating handle having a first section and a second section, which slide longitudinally in relation to one another to selected positions in a range between a most forward position and a most rearward position;
a tube, extending from the second section of the operating handle, divided in cross section by means of a longitudinally extending wall into first and second segments;
the first segment of the tube containing a viewing means connected to the second section of the operating handle and extending along the length of the first sector of the tube, and providing an open passageway adjacent the viewing means for the supply of aspirating fluid to the surgical site;
the second segment of the tube containing a cutting tool connected by an extension means to the first section of the operating handle, the extension means having a sufficient length to extend the cutting tool to a distal end of the second segment of the tube when the first and second sections are at the most rearward position and to extend the cutting tool beyond the distal end at the most forward position of the sections, and providing a passageway for removal of aspirating fluid and surgical morsels.
In another embodiment described hereafter the second passageway has a valve mechanism to control the flow of outgoing aspirating fluid and surgical debris.